The present invention generally relates to on-board vehicle computer systems and, more particularly, to a system and method for monitoring on-board vehicle computer systems.
For over a decade, computers have been used on vehicles, such as automobiles and trucks, to control particular operations of one or more mechanical vehicle systems. In this regard, one of the first and still principal applications of vehicle computer technology has been to control various aspects of the engine used to drive the vehicle. In recent years, computers have also come to be used in a wide variety of vehicle systems, such as transmission systems, brake systems, suspension systems, operator control panels and even motorized seats. An example of one such computerized vehicle system is described in Leising et. al. U.S. Pat. No. 4,875,391, issued on Oct. 24, 1989, entitled "Electronically-Controlled, Adaptive Automatic Transmission System". This commonly assigned patent is hereby incorporated by reference. As described in this patent, the vehicle transmission system includes a computer circuit which controls a plurality of solenoid-actuated valves that regulate the flow of hydraulic fluid within the transmission.
Due to the complexity and inter-relationship between some of these vehicle systems, on-board computer communication systems have also been developed to enable data and other signals to be passed between particular vehicle computers. These communication systems typically include a plurality of wires which are connected to the vehicle computers in a particular electronic configuration, generally referred to as a "bus".
One example of an appropriate vehicle bus structure is represented by the Chrysler Collision Detection ("C.sup.2 D") Serial Data Bus. This technology is described in the following publications and patents: SAE paper No. 860389, entitled "Chrysler Collision Detection (C.sup.2 D)--A Revolutionary Vehicle Network", by Frederick O. R. Miesterfeld, 1986; SAE paper No. 890529, entitled "The All-Adaptive Controls for the Chrysler Ultradrive Transaxle", 1989; U.S. Pat. No. 4,706,082, entitled "Serial Data Bus For Intermodule Data Communications," which issued on Nov. 10, 1987; and U.S. Pat. No. 4,719,458, entitled "Method of Data Arbitration and Collision Detection In A Data Bus," which issued on Jan. 12, 1988; and U.S. Pat. No. 4,739,323, entitled "Serial Data Bus For Serial Communication Interface (SCI), Serial Peripheral Interface (SPI) and Buffered SPI Modes of Operation," which issued on Apr. 19, 1988; and U.S. Pat. No. 4,739,324, entitled "Method for Serial Peripheral Interface (SPI) in a Serial Data Bus," which issued on Apr. 19, 1988; and U.S. Pat. No. 4,742,349 entitled "Method for Buffered Serial Peripheral Interface (SPI) in a Serial Data Bus", which issued on May 3, 1988. These co-assigned patents and the identified publications are all hereby incorporated by reference.
In this regard, it should be noted that the engine controller and the transmission controller discussed in the above referenced U.S. Pat. No. 4,875,391 are both connected to the C.sup.2 D Serial Data Bus. This Serial Data Bus may also be accessible to off-board vehicle computers through one or more diagnostic connectors on the vehicle. In this regard, it should be appreciated that any vehicle bus structure needs to be accessible to off-board computer systems in order to permit the bus itself to be tested and permit direct access to and communication with any of the vehicle computers tied to the vehicle bus. An example of the use of an off-board diagnostic tool used to monitor and program an on-board vehicle computer is the Berra et. al. U.S. Pat. No. 5,278,759, issued on Jan. 11, 1994, and entitled "System and Method for Reprogramming a Vehicle Computer". This commonly assigned patent is hereby incorporated by reference.
In addition, one or more of these vehicle diagnostic connectors also typically provide separate communication links or channels with both the vehicle's engine control computer and the vehicle's transmission control computer. These separate communication links are generally designed to conduct serial communications directly with these particular on-board vehicle computers during certain diagnostic procedures.
In any event, diagnostic connectors have been employed since engine computers were first used on vehicles to permit communication between on-board and off-board computers. Thus, for example, data being gathered by the on-board vehicle computer from various sensors (such as engine speed and manifold pressure) may be transmitted to an off-board computer for programmed or operator analysis.
In response to the heavy reliance on on-board computers, combined with a variety of systems employed by the various automobile manufacturers, future vehicles sold in the United States will soon have to provide a standardized diagnostic interface. This restriction is referred to as the OBDII/CARB requirement and includes new vehicles beginning in 1994 model year and all vehicles in the 1996 model year. The OBDII/CARB requirement offers a choice between a J1850 specification and an ISO9141 specification. The OBDII requirement, the J1850 standard, and the ISO9141 are hereby incorporated by reference.
Accordingly, it is a principal objective of the present invention to provide an advanced system and method for interfacing an on-board vehicle computer with a hand held diagnostic tool.
It is a more specific objective of the present invention to provide an advanced system and method for interfacing an on-board vehicle computer with a hand held diagnostic tool that is compatible with an existing proprietary communication system.
It is another objective of the present invention to provide an advanced system and method for interfacing an on-board vehicle computer with a hand held diagnostic tool that is additionally compatible with an ISO9141 specification which satisfies an OBDII/CARB requirement.
It is yet another objective of the present invention to provide an advanced system and method for interfacing an on-board vehicle computer with a hand held diagnostic tool that automatically recognizes and adapts to a proprietary communication system or an ISO9141 compatible system depending on which system is connected to the on-board vehicle computer.